1. Technical Field
The present invention relates to a driver apparatus for driving voltage-controlled switching elements.
2. Related Art
A known driver apparatus, as disclosed in Japanese Patent Application Laid-Open Publication No. 2010-246251, clamps a voltage between a gate and an emitter of a switching element (IGBT) at a clamping voltage when a current following through the switching element increases excessively.
In general, a current flowing through the switching element may increase more excessively when the switching element is turned off than when the switching element is in an on-state with a voltage between the gate and the emitter of the switching element being kept constant. An amount of current flowing through the switching element when the switching element is turned off may increase since a maximum value of current allowed to flow through the switching element may increase with increasing voltage between the gate and the emitter of the switching element. Accordingly, clamping the voltage between the gate and the emitter of the switching element when the switching element is in the on-state with the constant voltage between the gate and the emitter and excessively large current is flowing through the switching element may lead to an increased reduction rate of current flowing through the switching element, which may cause an increased surge current.
In consideration of the foregoing, it would therefore be desirable to have a driver apparatus for driving a voltage-controlled switching element by manipulating a voltage at a switching control terminal of the switching element in response to a received operation signal, which is capable of advantageously suppressing a surge voltage.